mp7646

This morning the battery was dead on my 93 LS400. I tried charging it but when I turned the key nothing happened. No lights, horn nothing. Only dash lights. The battery is over 5 years old so I bought a new battery and installed it. The car is still dead. Dash lights still work but no dome lights nothing. When I connected the new battery the alarm went off. Turning the ignition key to on stopped the alarm but the car is still dead. Any tips would be greatly appreciated.
Thanks,
Michael

mp7646

Thanks,
The car is 22 years old with 160,000 miles. Looks and runs like new except the main remote locking keys fell apart. I have to lock and unlock the car manually. Last night I was using the valet key and the car was dead. I was gone for a couple of days and something set the alarm off. Today I locked and unlocked the car with the main key not the valet key. The car started and ran fine. Duh!